Add blocksize functions to physical memory. Fix the port we were using in the proces...

Add blocksize functions to physical memory.  Fix the port we were using in the process loader.

mem/physical.cc:
    Implement the blockSize function, return VMPageSize for the physical memory
mem/port.hh:
    Add a function to get a pointer to a peer, needed for initVirtMem to work in the loader.
sim/process.cc:
    The way the translating port is setup we don't want the memory port, we want the peer port associated with that memory.  We may need to revisit this.

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extra : convert_revision : 46a51d448d1683db7bd5afe64adbe167a5743060